Pump

pump
An hydraulic machine, variously constructed, for raising or transferring fluids, consisting essentially of a moving piece or piston working in a hollow cylinder or other cavity, with valves properly placed for admitting or retaining the fluid as it is drawn or driven through them by the action of the piston.
For various kinds of pumps, see air pump, chain pump, and force pump; also, under lifting, Plunger, Rotary, etc. Circulating pump See well.
Origin: Akin to D. Pomp, G. Pumpe, F. Pompe; of unknown origin.
The hollow muscular organ located behind the sternum and between the lungs; its rhythmic contractions pump blood through the body; he stood still, his heart thumping wildly.